EPA Releases First Round of UCMR 5 Data

Today (8/17), EPA released the first data set from the Fifth Unregulated Contaminant Monitoring Rule (UCMR 5). Every five years, EPA is required under the Safe Drinking Water Act (SDWA) to monitor for contaminants that may be present in drinking water but are not subject to National Primary Drinking Water Regulations (NPDWR). All public water systems (PWSs) serving 3,300 or more people and a representative sample of 800 systems serving 25 to 3,299 people must test for these contaminants.

UCMR 5 includes 29 PFAS and lithium, including the six PFAS in the recently proposed NPDWR. The data released today is the first in 12 data sets that will be released quarterly between now and 2026. This initial release represents 7% of the total data that will be collected. EPA will use this data to make determinations about future actions for these substances under SDWA. The data can be found publicly in EPA’s National Contaminant Occurrence Database.

EPA’s summary of the data noted:

  • For PFOA and PFOS, 7.8-8.5% of samples had one or both of these contaminants above EPA’s Health Advisory (HA) levels;
  • One PWS measured HFPO-DA (“GenX chemicals”) above its HA level;
  • PFBS was not found above its HA level at any PWSs;
  • Nine of the remaining 25 PFAS were measured at or above their respective Minimum Reporting Levels (MRL) by 1-207 of
    approximately 2,000 PWSs.
  • No PWSs have reported results at or above their respective MRLs for the final 16 PFAS.
  • 22% of PWSs reported lithium results above EPA’s health reference level.